Process of



UNITED STATES PATENT rica.

PETER DE VILLIERS, OF ST. LEONARDON-SEA, ENGLAND.

PROCESS .OF APPLYING ALLOYS TO STEEL.

SPECIFICATION forming part of Letters Patent No. 265,221, datedSeptember 26, 1882,

Application iiled September 3, 1881. Renewed September 1, 1882.

(No specimens.) Patented in England August 20, 1880, No.

3,394; in Canada April lil, 1881, No. 12,620; inBelg'ium April 15, 1881,No. 54,221; in Italy April 16, 1881, and in France April To all whom itmay concern Be it known that I, PETER DE VtLLIERs, of St.Leonard-oirSea, England, doctor of medicine, have invented a new anduseful improved process for applying alloys to steel or other metal withor without a silver or other coating or covering, (for which I haveobtained a patent in Great Britain, No. 3,394, hearing date 20th August,1880; in France, bearing date 19th April, 1881 No. 141,254; in Belgium,bearing date 15th April, 1881, No. 54,221; in Italy, bearing date 16thApril, 1881, and also in Canada, bearingdate 13th April, 1881, No.12,620,) of which the following is a specification.

My invention relates to a process for applying an inoxidizable alloy tosteel, iron, or other metal or alloy,which may be afterward coated orcovered with silver or other metal, or left without such a coating orcovering, as may be desired.

The said invention is chiefly designed for applying to knives and otherarticles the inox idizable alloy forming the subject-matter of LettersPatent granted. to me since the tiling ot' the present application, andhearing date November 29, 1881, No. 250,326. In the specification of thesaid former patent I have stated that when tin is suitably combined withlead and silver in the proportions therein specified an alloy isproduced which will not only strong- 1y adhere to iron and steel, butwill impregnate these metals when they have een properly prepared toreceive the alloy, and I have given the proportions in which thesemetals should be mixed in such alloy.

In practicing my p'resentinvention I proceed as t'ollo\vsthat is to say:The tin is first melted, and when a brilliant whiteness of the surfaceof this metal indicates its thorough fusion the lead is added in agranular state, and the mixture is slowly stirred, preferably with a rodof very dry fir-wood. The silver, separately melted, is then added toand mixed in like manner with the compound. At this moment the tireunder the melting-pot or crucible containing the alloy must be quicklyincreased till the surface of the metal has a slight yellow tinge. It isthen rapidly stirred and run into molds to form ingots.

Then I have the choice between iron or steel for the manufacture of anyarticle to be treated with my improved alloy 1 take the purest steelused for marmfacturing purposes. One very important use of my inventionis its application to table-cutlery. For this purpose I proceed asfollows: The blade is immersed in a bath of a solution of muriatic orsulphuric acid in the following proportions, by weight, viz: onehundred(100) parts of distilled water or filtered rain-water, and from one (1)to ten (10) parts, by weight, of muriaiic acid or of sulphuric' acid.The blade mustremain in this bath fora longer or shorter time, accordingto its thickness, in order that it may be slowly and thoroughlypenetrated by the same, this result being indicated by the appearance ofspots on the'surface of the metal. Instead of the acid solution, I mayuse aqua-fortis, the time of immersion in this case being very short.When the blade is withdrawn from the bath it must immediately be plungedinto pure water, to be quickly and completely washed, and then it iswiped and dried as rapidly as possible with a piece of old linen, softleather, or a very dry sponge. It is then subjected for about liveminutes to a dry heat in a furnace or oven heated to or centigrade. Itis then withdrawn and again wiped.

The preceding operations have for their object the preparation of theiron or steel for impregnation with the alloy, the result being that thesaid iron or steel is roughened or provided with a rugged surface, asthough tilled with a large number of small cavities, the structure ofthe surface being as though the pores of the metal were enlarged ordistended. In iron, unless this metal is of excellentquality,theroughened or rugged surface or the size of the pores is variable, andsometimes there are defective parts, which make the subsequentoperations difficult. In steel the roughened or rugged surface issubstantially uniform, and the subsequent operations are eifected withbut little difficulty, and for this reason I prefer to employ steel incarrying out my invention.

The knife-blade. or other article, alter its preparation as abovedescribed, is immersed in a metallic bath composed of the alloy madeaccording to one or the other of the formulas given in the said formerspecification. The ingotsare melted over a moderate tire in a crucibleor pot formed of plumbago or refractory clay, and not in an iron vessel,as particles of the iron would mix with the alloy and render the sameliable to oxidize in the open air, thus impairing the appearance of theimpregnated knife'bladc or other article. The iron or steel, previous toimmersion in the metallic bath or alloy. must be heated to a temperatureof or centigrade. The bath must be perfectly liquid, and is stirred witha dry rod of fir-wood or poplar, and the surface of the molten alloymust present a fine silverwhite color, which is obtained by slow fusionand by stirringonly when the whole of the mass is liquefied. If theseprecautions are observed, the alloy will fill the before-mentioneddistended pores or the roughened or rugged surface oi the metal in aneffective manner, andprovidean efticient union between the metal and thealloy coating. The length of time that the metal to be coated issubjected to the acid solution or bath will depend upon the dimensionsof the article being treated. For example, the metal used for tnaking anordinary kniteblade or similar thin object will be subjected to the acidsolution or bath for about tivc minutes. while a piece of steel,say,one-eighth of an inch thick will be subjected to the acid solution orbath for about ten minutes. When withdrawn from the metallicbath theblade or other article of iron or steel is at once immersed in coldwater, oris otherwise properly treated to harden or temper it or torestore its temper, as required. If left in the cold water for too longa time, the metal sometimes becomesbrittle; butcarefulness on the partof the operator will prevent anyditliculty ofthis kind. The blade orother article, having been wiped and dried without the application ofheat, is polished in any suitable manner. It will then have thewhiteness and luster of silver, and will have a ring or sound analogousto thatof the latter metal, and maybe considered inoxidizable underordinary atmospheric conditions; but by the further treatmenthereinafter dc scribed these articles can be rendered thoroughly proofagainst oxidation or corrosion by ordinary acids-such as vinegar, lemon,or other fruit acids or pickles-so that when used in contact with thesame, or with fish, fatty matters, or culinary preparations of any kind,or with potable liquids or the like, th 'y will not impart flavor nortaste thereto, nor will the taste or smell of any of these substancesadhere to such articles. To attain these results, I take the blades orother articles that have been prepared and subjected to the alloy, asabove described, and rub the same gently with an amalgam which Icompound as follows, viz: mercuty, sixty ((30) parts; tin, thirtynine(39) parts; silver, one (1) part-one hundred (1H0) parts, by weight. 1make this amalgam as follows-that is to say, I first melt the tin, andwhen the same is rendered properly liquid pulverized silver is thrown li l upon its surface and melts somewhat rapidly. The whole is thenstirred by means of a very dry rod offir-wood, and the mercury is addedgradually with continual stirring. The mixture is then allowed to coolin an tarthenware vessel. It is then reheated over a moderate fire,without stirring. This operation of reheating is repeated three or fourtimes. The amalgam is then ready, and has to be kept in a close vesseland protected from light. The polished articles must be lightly rubbedwith this amalgam by means of a soft cotton cloth or other suitablematerial previously impregnated with a solution containing one (1) partof nitrate of potassa (saltpeter) in one hundred (100) parts of filteredwater, by weight. This cloth is to be used only when thoroughly dry, andrendered supple by rubbing it between the hands. YVhcn once permeated bythe amalgam it will serve for an indefinite time.

The abovealescribed successive operations result in the incorporation orunion with the iron or steel, first, of the metals of the alloy, andthen of the amalgam. The tollowlng proceedin s complete and renderpractically perfect the series of combinations whereby an article orobject to which my in\ ention is applied has the various metals thereofas intimately and inse mral'ily united as in any true alloy. Thearticles of iron or Sll0t*l |)lv|)tll'eil up to this pointthat is tosay, by the application of the amalgamare finished by elcclro-depositionor otherwise, with a coating ol'covet'itlg of silver, which is combinedor incorporated by the aid of the amalgam with the substance of thearticle itself and the alloy with which the same is impregnated, andthereby my invention differs frotn the processes hitherto known, whichonly cause a simple superposition of the silver or other coating metalupon the surface of the metal covered thereby.

If the tinal coating or covering of the knifeblade or other article isto be of gold, I prefer to apply this metal by .electro deposition uponthe surface of the silver.

In cases where it is desira le to econotnizc the process above describedI make an alloy of tin and lead without the silver, in the proportion ofabout ninety (90) parts of tin and ten (10) parts of load, and immersein it the iron or steel in the manner above described, and then applythe amalgam and the silver coating or covering; but I do not think theresult in this case will be so satisfactory as when the al oy usedconsists of silver, lead, and tin in the proportions set forth in thesaid specification. l urthermore,asIamawarcthat many persons stronglyobject to the use of any articles in whose manufacture the slightestparticle of mercury has been used, I may modify my invention bysubstituting for the application of the amalgam thei'ollowingtreatmentthat is to say, 1 immerse the articles after they have beenimpregnated with the aforesaid alloy in a bath composed of cyanide ofpotassium, six (6) parts;'bisulphide of soda, two (2) parts; andcarbonate of soda, eight. (8) parts,

by weight, dissolved in water, preferably rainwater, to which I addprotochloride of zinc, two (2) parts, and acetate of copper, one (l)part, by weight, also dissolved in rainwater, but in only aboutone-quarter of the quantity or volume of the first-named solution.

The objects or articles prepared as above described, but not treated bythe amalgam, are placed in the said bath, which is connected with astrong electric battery, and will rapidly acquire a beautiful white butnot shining appearance. They should not remain in the said bath morethan a few minutes. Immediately after being removed from the bath theyshould be carefully dried and placed in a bath of pure silver, andfinished as above described.

I may apply my invention not only to iron and steel, but also to bronze,German silver, and other metals and alloys which are capable ofresisting the heat required for the divers operations above described,and I thereby increase the hardness and sonorousness of such metals.

I have hereinabove chiefly described my invention as applied toknife-blades; but I wish it clearly understood that other objects orarticles can be treated in the same manner with great advantage. Thesaidinvention is applicable to household utensils used for culinary orother purposes wherein inoxidability is desirable likewise to a greatnumber of objects or articles used in the arts and manufactures.

My process is inexpensive, and the difference in price between anyarticles or objects manufactured in the best manner by any processeshitherto known and similar articles or objects produced or finished bymy said process is in favor of the latter. The articles preparedby myprocess do not require the frequent or severe rubbing or polishing whichin the case of ordinary table cutlery and other articles necessitates aconsiderable expenditure of time and labor and soon renders knives orother articles subjected thereto unfit for use, whereas a knife treatedaccording to my process will be kept clean and bright by simple washingwith Warm Water and without the use of a knife-board or a cleaning orpolishing machine, and such knives may be sharpened in the usual manner,and will keep their edge like pure steel.

It will thus be obvious that by my invention table-cutlery and otherarticles are rendered practically imperishable with ordinary care, andwill retain the appearance and brilliancy of polished silver.

Having thus described my invention, what I claim is 1. The processherein described of coating metal, which consists in roughening thesurface of the articles to be coated by acids and heat, as set forth,again heating the metal, and then. subjecting the metal thus prepared tothe action of a molten bath of an alloy of lead, tin, and silver whichfills the roughened surface of the metal, all substantially in themanner and for the purposes set forth.

2. The process herein described of coating metal, which consists inroughening the surface of the articles to be coated by acid and heat, asset forth, again heating the metal, subjecting it to the action of amolten bath of an alloy of lead, tin, and silver, applying a secondarycoating of amalgam, and then electroplating the same with silver,substantially in the manner and for the purposes set forth.

PETER DE VILLIERS.

Witnesses:

HENRY BENSON, Belle Vue, Hastings, Solicitors Clerk.

GEO. S. D. HILDER, 64 Stonefield Road, Hastings, Solicitors Clerk.

